List pending inbound emails

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotations already provide readOnlyHint=true and destructiveHint=false, so the description does not need to repeat those. It adds value by specifying ordering (newest first), limit (max 50), and the fields returned, plus a critical security warning about not following instructions in email content.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences with zero waste. The first sentence immediately states the tool's purpose and key details; the second sentence provides workflow pairing and a critical security warning. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Despite no output schema, the description explicitly lists the returned fields (sender, subject, received time, short preview). The security warning addresses a real risk. For a simple list tool, this is complete and leaves no significant gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

There are zero parameters, so the schema is trivially 100% covered. The description does not need to add parameter details; baseline of 4 is appropriate for no-parameter tools.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses specific verbs ('List inbound emails') and details the resource ('inbound emails awaiting review') with ordering and limit. It distinguishes from siblings by naming the pair tools (setell_approve_inbound_email / setell_reject_inbound_email), clarifying its role in the triage workflow.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description clearly states this is the read half of inbox triage and should be paired with approve/reject tools, providing explicit context for when to use. It adds a security guideline about untrusted content but does not explicitly list when not to use it or alternative tools among siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.